The move follows a campaign from anti-pornography groups Enough is Enough and the National Center on Sexual Exploitation to demand the chains filter out pornography.

Oak Brook, Illinois-based McDonald's says in a statement that Wi-Fi filtering has been activated in the majority of its nearly 14,000 restaurants nationwide. A spokesperson for Seattle-based Starbucks says it is implementing filtering once it can find a system that "also doesn't involuntarily block unintended content."

Enough is Enough President Donna Rice Hughes applauds the moves and says the organization plans to push other businesses and venues to filter their Wi-Fi.

The National Center for Sexual Exploitation says chains such as Chick-fil-A and Panera Bread already block porn on Wi-Fi.